How can I make a perfect sweep with bevel object in Bezier curve(3d) (Pipe)
Short answer: No you cannot. It's a known limitation of the current system and unfortunately there is no current way around it.

This is currently planned to be improved as part of 2016 GSOC Bezier Curve Improvements, but if it will ever be successfuly done or actually land in an official Blender release remains to be seen.

Either use a 2D curve, which causes no distortions, add extra control points near the tight bends to minimize the deformed area or where possible use separate segments. See this answer for more details.

Alternatively if you want to use simple pipes with exclusively straight or angled segments and don't mind using mesh objects instead try using one of the builtin addons Pipe Joints

https://blender.stackexchange.com/a/53486/19307